RegiStax

Free image processing
software

RegiStax
5.1: New and changed features list

Although development of
RegiStax 5.1 originally started due to a request to add functionality
to process RAW y800 AVIs we have been working on a full revision of
many aspects of the software. The update is therefore not a real minor
update. We explain functionality of several of the new/changed features
in these pages. On this page you can see a (nearly) complete list of
all the changes compared to the original V5 release in march 2009.

General improvement in functionality
-Debayering of Y800 AVI's larger than 2Gb (added in 5.1.0.2)
-useage of PNG as a flatfield/darkframe was not always working as expected.
-useage of files single colour files. If you load files with names
ending in _R,_G,_B,_L (red,green,blue,luminosity, for instance
jupiter_G.bmp) the program now uses these files without crashing.

Changes at the specific RegiStax Stages

ALIGN STAGE
-Lefttab Options section Additional-Wait while loading a single image, this allows the user to treat a single image without directly going to the Stacking Stage
-Play Sounds, this
will use default windows sounds to signal that
Alignment/Optimizing/Stacking is finished or when a special RegiStax
message pops up.
-Swap red and Blue,added for the special occasions where swapping the channels is necessary (IR imaging)
-Use CameraWhiteBalance, when processing RAW frames from DSLR camera's this option will make the colour-balance identical to the original recording.

changed:
Setting the "Full Image"
option now will be remembered during processing. After
alignment/optimizing/stacking (when this option will be set OFF) on the
waveletpage this option will be active again if activated at the Align
Stage.

We have changed the PREFILTER setup, you can read more about that on this webpage

OPTIMIZE STAGE

On the optimize stage we also have added the PREFILTER
system allowing users to only use PREFILTER after initial
alignment or change parameters of the PREFILTER after for instance
"CREATE REFERENCE" or "REALIGN with PROCESSED".

Two new optimizer-methods
have been added, they are fundamentally different from the original
Squared/Absolute methods. Both of these methods compare the current
alignmentarea to the reference in a way that is less sensistive to for
instances changes in light-intensity. During testing we found
MutualInfo (Mutual Information if you want to search the internet for
the technique) is probably the best of the 4 available methods.

The graphs during optimisationare
now always expanded maximally. This means that the highest/lowest
value recorded will correspond to the maximum-minimum of the
graphscale. You will during optimisation see the graphs sometimes
change in scale. The large advantage of this is that differences will
be shown in maximum detail, especially in the Stacking stage (where
this information is also used) this is helpfull. Additionally the
graphs also show the minimum-maximum values in the graphcaption.

The drizzle-function
has been changed and now works as planned, to achieve this we have
locked the magnification factor of Drizzle to 2. You can read more on
this webpage

When using Create-Reference
in RegiStax V5 the program would not remember the previously used
setting if this was larger than 100 frames. That has been changed in
V5.1

STACKING STAGE
-Option under section Sigmastacking:
added: stack above average intensity.
This can be used to show improve average image-intensity for
image-sequences with temporary bright/dark features (passing meteors).

Saving Registered
This section has been changed a great deal. We have added the
option to saving only the Region Of Interest if the user has specified
this. This is handy to create for instance a new AVI (or set of
frames) with only the topic of interest (for instance a planet).
Next to this you can now also save the registered frames as PNG files.
So currently you can save the registered frames as an AVI (8bit), BMP
files (8bit) and PNG (16bit). Saving to PNG works rather different from
saving to AVI or BMP and will be slower. Needless to say that saving to
PNG is only usefull if the input format is also >8bits ! When saving
a registered set of frames you can also sort the frames according to
quality, for the single frame formats (BMP/PNG) the original filenames
will be used with a counter added to allow sorting them.
During testing some of us found it interesting to use the PREFILTER also
when saving an AVI for instance just to show certain aspects of the
frames. Especially Pre-gradient has interesting proportions to study
the way turbulence manifests itself on frames.

FramelistTheframelist now has a section on top where you can read for the alignpoints how large the shifts (X and Y) are.

DrizzlingThe new drizzling function allows users to activate it on the Stacking stage, read more about it at this webpage

Normalisation of Frame intensity
This function is now by default on, during testing we found out that
many of the problems users had with seams can be cleared using
normalisation of the frame-intensity. This function makes sure that
frames (and sections of a frame) are equal in average intensity. This
is a rather important change and more can be seen at this webpage

Stackgraphs
Thusfar the StackGraph(s) would shows the image-differences on a scale
from 0 to the maximum recorded difference. This is logical if the least
recorded difference is indeed 0, but if the user was using a created
referenceframe the most alike looking frame was often not 0. When you
want to use the stackgraphs it sometimes was difficult to select the
precise amount of frames. Next to this the new optimizer-methods work
so different that we now have changed the way the stackgraphs are
shown. They will show only the minimum to maximum values and not
necessarily start at 0. That gives the users maximum control to remove
frames from the stack.

WAVELET STAGE
When "realigning with processed" you can now also do this if you have been using resampling or drizzling.
A new technique is used to do the "auto balancing" for RGB images, this white balance technique is explained in more detail at this webpage
When you are using drizzling or resampling the "show alignpoints" is now showing correct size/position of the alignpoints.
When using larger gaussian filters
it was possible to get "edges" appearing in the image, we have now
expanded the gaussian section even further to prevent this from
happening.